How do you apply stucco to curved walls or arches on an Ottawa home?

Curved walls and arches are among the most skill-intensive stucco applications, and they're more common on Ottawa homes than you might think — from arched entryways in Rockcliffe Park heritage homes to curved bay windows in Westboro and rounded turret features on custom builds in Manotick.

Stucco Application on Curved Surfaces

Lath installation is where the curve really matters:

• Standard expanded metal lath is somewhat flexible and can be bent to follow gentle curves (radius of 600 mm or more) without modification. For tighter curves, the lath needs to be scored or kerfed on the back side to allow it to bend smoothly without buckling.
• On very tight curves — arched window tops, rounded column wraps — self-furring dimpled lath works better because the dimples act as flex points while maintaining the necessary standoff from the wall surface.
• Lath must be overlapped by at least 25 mm at every joint and tied with galvanized wire ties every 150 mm on curves. Curves put more stress on lath joints than flat surfaces, so extra fastening prevents popping and cracking later.

Applying the stucco coats on curves:

• Scratch coat: Applied with a standard flat trowel and immediately shaped to follow the curve using a flexible trowel or a custom-bent template. Thickness control is harder on curves — the tendency is to build up too thick on the inside of concave curves and too thin on convex surfaces. Experienced contractors check with a flexible straightedge as they work.
• Brown coat: This is where the curve gets refined. Ottawa contractors who specialize in curved work often make custom screeding tools from flexible materials — a piece of 6 mm plywood or a sheet of rigid foam cut to the desired profile and bent to the radius. This allows them to screed the brown coat to a consistent thickness across the entire curve.
• Finish coat: Texture application on curves requires a modified technique. Sprayed finishes (like a dash or splatter texture) work well because they follow the curve naturally. Trowelled finishes need a flexible steel or rubber trowel to maintain even pressure across the curved surface.

Special considerations for Ottawa's climate:

• Curved surfaces collect and concentrate water differently than flat walls. The bottom of a concave curve is a natural water collection point — it needs extra attention to drainage and may benefit from a drip screed at the low point.
• Thermal stress concentrates at curve transitions (where a curved wall meets a flat wall). Ottawa's extreme temperature range makes these stress points prone to cracking. A control joint at each transition point is essential.

Curved stucco work commands a premium — expect to pay 30% to 50% more per square foot than flat wall stucco. For Ottawa homes, that means curved sections typically run $15 to $24 per square foot versus $10 to $16 for flat surfaces. Arched entryways are usually quoted as a unit price, typically $800 to $1,500 per arch depending on size and complexity.

Not every stucco contractor takes on curved work — it requires genuine craftsmanship. When getting quotes in Ottawa, ask to see examples of curved stucco they've completed, specifically how the curves look after surviving at least one winter.

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Looking for experienced contractors? The Ottawa Construction Network connects Ottawa homeowners with qualified professionals:

• Luxe Painting and Renovations
• RenoMotion Inc.
• Capital City Drywall
• DC Stucco & Parging
• MAK Construction and Development Inc

View all contractors →